Word by Word Analysis

إِنَّ ٱلَّذِينَ كَفَرُوا۟ بَعْدَ إِيمَـٰنِهِمْ ثُمَّ ٱزْدَادُوا۟ كُفْرًا لَّن تُقْبَلَ تَوْبَتُهُمْ وَأُو۟لَـٰٓئِكَ هُمُ ٱلضَّآلُّونَ 90

Indeed, those who disbelieve [i.e., reject the message] after their belief and then increase in disbelief - never will their [claimed] repentance be accepted, and they are the ones astray.